/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.search.aggregations.pipeline;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.SortedNumericDocValuesField;
import org.apache.lucene.document.SortedSetDocValuesField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.tests.index.RandomIndexWriter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.BytesRef;
import org.opensearch.common.CheckedConsumer;
import org.opensearch.common.settings.Settings;
import org.opensearch.index.mapper.KeywordFieldMapper;
import org.opensearch.index.mapper.MappedFieldType;
import org.opensearch.index.mapper.NumberFieldMapper;
import org.opensearch.index.query.MatchAllQueryBuilder;
import org.opensearch.script.MockScriptEngine;
import org.opensearch.script.Script;
import org.opensearch.script.ScriptEngine;
import org.opensearch.script.ScriptModule;
import org.opensearch.script.ScriptService;
import org.opensearch.script.ScriptType;
import org.opensearch.search.aggregations.AggregatorTestCase;
import org.opensearch.search.aggregations.bucket.filter.FiltersAggregationBuilder;
import org.opensearch.search.aggregations.bucket.filter.InternalFilters;
import org.opensearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.opensearch.search.aggregations.metrics.AvgAggregationBuilder;
import org.opensearch.search.aggregations.support.ValueType;

import java.io.IOException;
import java.util.Collections;
import java.util.Map;
import java.util.function.Consumer;

import static org.hamcrest.CoreMatchers.equalTo;

public class BucketScriptAggregatorTests extends AggregatorTestCase {
    private final String SCRIPT_NAME = "script_name";

    @Override
    protected ScriptService getMockScriptService() {
        MockScriptEngine scriptEngine = new MockScriptEngine(
            MockScriptEngine.NAME,
            Collections.singletonMap(SCRIPT_NAME, script -> script.get("the_avg")),
            Collections.emptyMap()
        );
        Map<String, ScriptEngine> engines = Collections.singletonMap(scriptEngine.getType(), scriptEngine);

        return new ScriptService(Settings.EMPTY, engines, ScriptModule.CORE_CONTEXTS);
    }

    public void testScript() throws IOException {
        MappedFieldType fieldType = new NumberFieldMapper.NumberFieldType("number_field", NumberFieldMapper.NumberType.INTEGER);
        MappedFieldType fieldType1 = new KeywordFieldMapper.KeywordFieldType("the_field");

        FiltersAggregationBuilder filters = new FiltersAggregationBuilder("placeholder", new MatchAllQueryBuilder()).subAggregation(
            new TermsAggregationBuilder("the_terms").userValueTypeHint(ValueType.STRING)
                .field("the_field")
                .subAggregation(new AvgAggregationBuilder("the_avg").field("number_field"))
        )
            .subAggregation(
                new BucketScriptPipelineAggregationBuilder(
                    "bucket_script",
                    Collections.singletonMap("the_avg", "the_terms['test1']>the_avg.value"),
                    new Script(ScriptType.INLINE, MockScriptEngine.NAME, SCRIPT_NAME, Collections.emptyMap())
                )
            );

        testCase(filters, new MatchAllDocsQuery(), iw -> {
            Document doc = new Document();
            doc.add(new SortedSetDocValuesField("the_field", new BytesRef("test1")));
            doc.add(new SortedNumericDocValuesField("number_field", 19));
            iw.addDocument(doc);

            doc = new Document();
            doc.add(new SortedSetDocValuesField("the_field", new BytesRef("test2")));
            doc.add(new SortedNumericDocValuesField("number_field", 55));
            iw.addDocument(doc);
        },
            f -> {
                assertThat(((InternalSimpleValue) (f.getBuckets().get(0).getAggregations().get("bucket_script"))).value, equalTo(19.0));
            },
            fieldType,
            fieldType1
        );
    }

    private void testCase(
        FiltersAggregationBuilder aggregationBuilder,
        Query query,
        CheckedConsumer<RandomIndexWriter, IOException> buildIndex,
        Consumer<InternalFilters> verify,
        MappedFieldType... fieldType
    ) throws IOException {

        try (Directory directory = newDirectory()) {
            RandomIndexWriter indexWriter = new RandomIndexWriter(random(), directory);
            buildIndex.accept(indexWriter);
            indexWriter.close();

            try (IndexReader indexReader = DirectoryReader.open(directory)) {
                IndexSearcher indexSearcher = newIndexSearcher(indexReader);

                InternalFilters filters;
                filters = searchAndReduce(indexSearcher, query, aggregationBuilder, fieldType);
                verify.accept(filters);
            }
        }
    }
}
